Organic light emitting display device and method of manufacturing the same

ABSTRACT

An organic light emitting display device includes: a thin film transistor disposed in a display area of a substrate; an insulating layer disposed on the thin film transistor; an organic light emitting element disposed on the insulating layer and connected to the thin film transistor; and an encapsulation layer covering the organic light emitting element. The encapsulation layer includes: a first inorganic layer extending from the organic light emitting element to a non-display area; an organic layer disposed on the first inorganic layer; a second inorganic layer extending from the organic layer to the non-display area; and an organic pattern layer disposed between the first inorganic layer and the second inorganic layer and spaced apart from the organic layer in the non-display area. At least a part of the first inorganic layer and at least a part of the second inorganic layer may contact each other in the non-display area.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Application Serial No.17/211,007 filed on Mar. 24, 2021, which is a divisional application ofU.S. Pat. Application Ser. No. 16/246,865, filed on Jan. 14, 2019, nowU.S. Pat. No. 10,991,909, issued Apr. 27, 2021, which claims priorityunder 35 U.S.C. §119 to Korean Patent Application No. 10-2018-0008287,filed on Jan. 23, 2018, in the Korean Intellectual Property Office(KIPO), the disclosures of which are incorporated by reference herein intheir entirety.

TECHNICAL FIELD

Exemplary embodiments of the present invention relate to an organiclight emitting display device, and a method of manufacturing the same.

DISCUSSION OF RELATED ART

Display device is an apparatus capable of providing a user with visualinformation such as an image or a text. Currently, display devices arebeing manufactured into various forms in order to generate various typesof images and texts.

Organic light emitting diode (OLED) display devices areself-light-emitting type display devices which electrically excite anorganic compound to emit light. Since such OLED display devices may bedriven at a low voltage, are easy to be slimmed down, have a wideviewing angle, and are quick in response, thus capable of solving issuesof Liquid-crystal-display (LCD) devices, they are garnering a lot ofattention as next generation display devices.

In recent times, a thin film encapsulation layer including an organiclayer and an inorganic layer has been used as a means for sealing anorganic light emitting element to achieve slimness and/or flexibility ofthe OLED display devices. The thin film encapsulation layer has amultilayer thin film structure in which organic layers and inorganiclayers are alternately laminated. When the organic layer is exposedthrough an end portion of the thin film encapsulation layer, the exposedportion may become an infiltration path for moisture and oxygen. Thepenetration of external moisture and oxygen to the OLED display devicemay be delayed or blocked, when the end portion of the thin filmencapsulation layer is sealed with an inorganic layer. However, whensuch inorganic layers contact each other in at least a part of thesealing layer, there is a possibility that stress is concentrated at theinterface between the inorganic layers and cracks are generated.

SUMMARY

Exemplary embodiments of the present invention may be directed to anorganic light emitting display device partially modified in terms of theshape of an encapsulation layer to absorb stress caused by an externalimpact, to suppress crack generation by imparting flexibility, andrealizing a robust structure of the encapsulation layer, and to a methodof manufacturing the organic light emitting display device.

According to an exemplary embodiment of the present invention, anorganic light emitting display device includes: a substrate including adisplay area and a non-display area; a thin film transistor disposed onthe substrate in the display area; an insulating layer disposed on thethin film transistor; an organic light emitting element disposed on theinsulating layer and connected to the thin film transistor; and anencapsulation layer covering the organic light emitting element. Theencapsulation layer includes: a first inorganic layer disposed on theorganic light emitting element and extending from the organic lightemitting element to the non-display area; an organic layer disposed onthe first inorganic layer; a second inorganic layer disposed on theorganic layer and extending from the organic layer to the non-displayarea; and an organic pattern layer disposed between the first inorganiclayer and the second inorganic layer so as to be spaced apart from theorganic layer in the non-display area. At least a part of the firstinorganic layer and at least a part of the second inorganic layer maycontact each other in the non-display area.

At least a part of the organic pattern layer may overlap the insulatinglayer in a plan view.

The organic pattern layer may include a material substantially the sameas a material which the organic layer includes.

The organic layer may include at least one kind of organic materialselected from: acrylic resins, methacrylic resins, isoprene resins,vinyl resins, epoxy resins, urethane resins, cellulose resins, phenyleneresins, and imide resins.

The organic pattern layer may have a width of about 10 µm or more and athickness of about 0.1 µm or more.

The first inorganic layer and the second inorganic layer may have asubstantially equal area in a plan view, and an area of the organiclayer may be less than an area of the first inorganic layer and an areaof the second inorganic layer.

The first inorganic layer and the second inorganic layer may eachindependently include at least one kind of inorganic material selectedfrom: silicon oxide, silicon nitride, silicon oxynitride, aluminumoxide, aluminum nitride, aluminum oxynitride, titanium oxide, titaniumnitride, tantalum oxide, tantalum nitride, hafnium oxide, hafniumnitride, zirconium oxide, zirconium nitride, cerium oxide, ceriumnitride, tin oxide, tin nitride, and magnesium oxide.

The organic light emitting display device may further include a damportion disposed in the non-display area of the substrate.

The insulating layer may include a side portion inclined in a directiontoward the dam portion.

The organic pattern layer may be disposed between the dam portion andthe inclined side portion of the insulating layer.

The organic pattern layer may be disposed at an area in which at least apart of the non-display area where the first inorganic layer and thesecond inorganic layer contact each other and at least a part of theinclined side portion of the insulating layer and the organic patternlayer overlap each other in a plan view.

The dam portion may be provided in plural and the plurality of damportions may have different heights.

The organic light emitting display device may further include a pixeldefining layer disposed between the insulating layer and theencapsulation layer, the pixel defining layer defining a pixel area ofthe organic light emitting element. The dam portion may include amaterial substantially the same as a material which at least one of theinsulating layer and the pixel defining layer includes.

The dam portion may include a first layer including a materialsubstantially the same as a material which the insulating layerincludes; and a second layer on the first layer, the second layerincluding a material substantially the same as a material which thepixel defining layer includes.

According to an exemplary embodiment of the present invention, a methodof manufacturing the organic light emitting display device includes:forming a thin film transistor in a display area of a substrate, thesubstrate including the display area and a non-display area; forming aninsulating layer on the thin film transistor; forming an organic lightemitting element on the insulating layer and connecting the organiclight emitting element with the thin film transistor; and forming anencapsulation layer covering the organic light emitting element. Theforming of the encapsulation layer includes: forming a first inorganiclayer to cover the organic light emitting element and to extend from theorganic light emitting element to the non-display area; forming anorganic layer on the first inorganic layer; removing a part of theorganic layer and leaving a part of the organic layer in the non-displayarea to form an organic pattern layer spaced apart from the organiclayer; and forming a second inorganic layer to cover the organic layerand to extend from the organic layer to the non-display area.

The first inorganic layer and the second inorganic layer may have asubstantially equal area in a plan view, and an area of the organiclayer may be less than an area of the first inorganic layer and an areaof the second inorganic layer.

The organic layer may be formed by one of an inkjet method, a slitcoating method, a screen printing method, an evaporation method, and achemical vapor deposition method.

The forming of the organic pattern layer may include forming the organicpattern layer by an ashing process using a cleaning mask.

The method may further include etching the insulating layer formed inthe non-display area of the substrate to form a dam portion.

The organic pattern layer may be disposed between the dam portion andone side portion of the insulating layer.

According to an exemplary embodiment of the present invention, anorganic light emitting display device includes: a thin film transistordisposed on a substrate in a display area, the substrate including thedisplay area and a non-display area; an insulating layer disposed on thethin film transistor, the insulating layer including an inclined sideportion in the non-display area; an organic light emitting elementdisposed on the insulating layer and connected to the thin filmtransistor; and an encapsulation layer covering the organic lightemitting element. The encapsulation layer includes: a first inorganiclayer disposed on the organic light emitting element and extending fromthe organic light emitting element to the non-display area; an organiclayer disposed on the first inorganic layer to cover a part of the firstinorganic layer; an organic pattern layer disposed on the firstinorganic layer, spaced apart from the organic layer, and overlapping atleast a part of the inclined side portion of the insulating layer in aplan view; and a second inorganic layer disposed on the organic layer,extending from the organic layer to the non-display area, covering theorganic pattern layer, and contacting the first inorganic layer in thenon-display area where the organic layer and the organic pattern layerare not disposed on the first inorganic layer.

The organic pattern layer may include a material substantially the sameas a material which the organic layer includes.

The first inorganic layer and the second inorganic layer may have asubstantially equal area in the plan view.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional view illustrating an organic light emittingdisplay device according to an exemplary embodiment of the presentinvention;

FIG. 2 is a cross-sectional view illustrating an organic light emittingdisplay device according to an exemplary embodiment of the presentinvention;

FIG. 3 is a scanning electron microscopy (SEM) photograph showing across-sectional structure of an organic light emitting display deviceincluding a conventional encapsulation layer;

FIG. 4 is an SEM photograph showing a cross-sectional structure of anorganic light emitting display device including an organic pattern layeraccording to an exemplary embodiment of the present invention; and

FIGS. 5, 6, 7 and 8 are cross-sectional views schematically showing amethod of manufacturing the organic light emitting display device ofFIG. 1 according to an exemplary embodiment of the present invention.

Since the drawings in FIGS. 1-2 and 5-8 are intended for illustrativepurposes, the elements in the drawings are not necessarily drawn toscale. For example, some of the elements may be enlarged or exaggeratedfor clarity purpose.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments will now be described more fully hereinafter withreference to the accompanying drawings. Although the present inventionmay be modified in various manners and have several embodiments,exemplary embodiments are illustrated in the accompanying drawings andwill be mainly described in the specification. However, the scope of thepresent invention is not limited to the exemplary embodiments and shouldbe construed as including all the changes, equivalents and substitutionsincluded in the spirit and scope of the present invention.

When a layer, area, or plate is referred to as being “on” another layer,area, or plate, it may be directly on the other layer, area, or plate,or intervening layers, areas, or plates may be present therebetween.Conversely, when a layer, area, or plate is referred to as being“directly on” another layer, area, or plate, intervening layers, areas,or plates may be absent therebetween. Further, when a layer, area, orplate is referred to as being “below” another layer, area, or plate, itmay be directly below the other layer, area, or plate, or interveninglayers, areas, or plates may be present therebetween. Conversely, when alayer, area, or plate is referred to as being “directly below” anotherlayer, area, or plate, intervening layers, areas, or plates may beabsent therebetween.

The spatially relative terms “below”, “beneath”, “lower”, “above”,“upper” or the like, may be used herein for ease of description todescribe the relations between one element or component and anotherelement or component as illustrated in the drawings. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the drawings. For example, in the case wherea device illustrated in the drawing is turned over, the devicepositioned “below” or “beneath” another device may be placed “above”another device. Accordingly, the illustrative term “below” may includeboth the lower and upper positions. The device may also be oriented inthe other direction and thus the spatially relative terms may beinterpreted differently depending on the orientations.

Throughout the specification, when an element is referred to as beingviewed “in a plan view”, the element is viewed from the above, and whenan element is referred to as being viewed “on a cross-sectional view”, across-sectional surface of the element that is cut vertically is viewedfrom the lateral side.

Throughout the specification, when an element is referred to as being“connected” to another element, the element is “directly connected” tothe other element, or “electrically connected” to the other element withone or more intervening elements interposed therebetween. It will befurther understood that the terms “comprises”, “comprising”, “includes”and/or “including” when used in this specification, specify the presenceof stated features, integers, steps, operations, elements, componentsand/or groups, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, componentsand/or groups thereof.

It will be understood that, although the terms “first”, “second”,“third” or the like may be used herein to describe various elements,these elements should not be limited by these terms. These terms areonly used to distinguish one element from another element. Thus, “afirst element” discussed below could be termed “a second element” or “athird element” and “a second element” and “a third element” may betermed likewise without departing from the teachings herein.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” may mean within one or morestandard deviations, or within ± 30%, 20%, 10% or 5% of the statedvalue.

Unless otherwise defined, all terms used herein (including technical andscientific terms) have the same meaning as commonly understood by thoseskilled in the art to which the present invention pertains. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an ideal or excessively formal sense unlessclearly defined in the present specification.

Some of the parts which are not associated with the description may notbe provided in order to specifically describe exemplary embodiments ofthe present invention and like reference numerals refer to like elementsthroughout the specification.

Hereinafter, an exemplary embodiment of the present invention will bedescribed with reference to FIG. 1 .

FIG. 1 is a cross-sectional view illustrating an organic light emittingdisplay device (hereinafter, “organic light emitting diode (OLED)display device” by way of example) 10 according to an exemplaryembodiment of the present invention.

Referring to FIG. 1 , an OLED display device 10 according to anexemplary embodiment of the present invention includes a substrate 101,a display unit 100 in a display area DA of the substrate 101, and anencapsulation layer 300 across the display area DA and a non-displayarea NDA for sealing the display unit 100.

The substrate 101 may include various materials. For example, thesubstrate 101 may include a transparent glass material including siliconoxide (SiO₂) as a main component. However, the present invention is notlimited thereto. For example, in an exemplary embodiment of the presentinvention, the substrate 101 may include a transparent plastic materialand have flexibility. Such a plastic material may include an insulatingorganic material selected from one of, for example, polyethersulphone(PES), polyacrylate (PAR), polyetherimide (PEI), polyethylenenaphthalate (PEN), polyethylene terephthalate (PET), polyphenylenesulfide (PPS), polyallylate, polyimide (PI), polycarbonate (PC),cellulose triacetate (TAC), and cellulose acetate propionate (CAP).

In the case of a bottom emission type where images are displayed towardthe substrate 101, it is necessary that the substrate 101 is formed of atransparent material. However, in the case of a top emission type whereimages are displayed in a direction opposite to the substrate 101, it isnot necessary that the substrate 101 includes a transparent material,and the substrate 101 may be either opaque or reflective and may includea metal material. In an exemplary embodiment of the present invention,the substrate 101 may include metals known in the art, and may includeat least one of, for example, iron (Fe), chromium (Cr), manganese (Mn),nickel (Ni), titanium (Ti), molybdenum (Mo), stainless steel (SUS),Invar alloys, Inconel alloys, and Kovar alloys.

The substrate 101 may include a display area DA in which light isemitted by the display unit 100 to realize images to be recognized byusers, and a non-display area NDA which corresponds to the remainingpart other than the display area DA. An organic light emitting element(hereinafter, “organic light emitting diode (OLED)” by way of example)100 b may be disposed in the display area DA, and a power wiring 220 forsupplying power to the OLED 100 b may be disposed in the non-displayarea NDA. In addition, a power supplier or a pad unit for applyingelectric signals from a signal generator to the display area DA may bedisposed in the non-display area NDA.

The display unit 100 will be described in more detail. A buffer layer102 may be disposed on the substrate 101. The buffer layer 102 mayprovide a planar surface on top of the substrate 101 and may blockforeign matter or moisture penetrating through the substrate 101. Forexample, the buffer layer 102 may include an inorganic material such as,for example, silicon oxide (SiO₂), silicon nitride (Si₃N₄), siliconoxynitride (SiON), aluminum oxide (Al₂O₃), aluminum nitride (AlN),titanium oxide (TiO₂), or titanium nitride (TiN), or an organic materialsuch as, for example, polyimide, polyester, or acrylic polymers, and mayhave a multilayer structure including the above-described materials. Thebuffer layer 102 is formed in the display area DA and may extend to thenon-display area NDA.

A thin film transistor 100 a and the OLED 100 b electrically connectedto the thin film transistor 100 a may be disposed in the display area DAover the buffer layer 102 on the substrate 101.

The thin film transistor 100 a may include an active layer 103, a gateelectrode 105, a source electrode 107, and a drain electrode 108.Hereinafter, the thin film transistor 100 a of a top gate type in whichthe active layer 103, the gate electrode 105, the source electrode 107,and the drain electrode 108 are sequentially disposed will be described.However, the present invention is not limited thereto. For example, inan exemplary embodiment of the present invention, various types of thinfilm transistors 100 a such as a bottom gate type may be employed.

The active layer 103 is disposed on the buffer layer 102. The activelayer 103 may include a semiconductor material known in the art, forexample, amorphous silicon or poly crystalline silicon. In an exemplaryembodiment of the present invention, the active layer 103 may include anorganic semiconductor material or the like. Alternatively, in anexemplary embodiment of the present invention, the active layer 103 mayinclude an oxide semiconductor material, and thus may include an oxideof a material selected from group 12, 13, or 14 metal elements such as,for example, zinc (Zn), indium (In), gallium (Ga), tin (Sn), cadmium(Cd), germanium (Ge), or combinations thereof. The oxide semiconductormaterials have high mobility, and thus may be suitable for OLEDapplication. In addition, since the oxide semiconductor materialsusually have wide-bandgaps, they can also be transparent.

A gate insulating layer 104 is disposed on the active layer 103, servesto insulate the active layer 103 from the gate electrode 105, and mayhave a single-layer structure or a multilayer structure, with each layerincluding at least one inorganic material of, for example, silicon oxide(SiO₂) and silicon nitride (Si₃N₄). The gate insulating layer 104 maynot only be disposed in the display area DA but also may extend to apart of the non-display area NDA.

The gate electrode 105 is disposed on the gate insulating layer 104, andmay be connected to a gate line for applying an on/off signal to thethin film transistor 100 a. The gate electrode 105 may include a lowresistive metal material known in the art. In consideration of closecontactness to an adjacent layer, surface flatness of a layer to belaminated thereon, and processability, the gate electrode 105 may have asingle-layer structure or a multilayer structure, with each layerincluding at least one of, for example, aluminum (Al), platinum (Pt),palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni),neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca),molybdenum (Mo), titanium (Ti), tungsten (W), copper (Cu), and the like.

An insulating interlayer 106 is disposed on the gate electrode 105, andinsulates the gate electrode 105 from the source electrode 107 and thedrain electrode 108. The insulating interlayer 106 may not only bedisposed in the display area DA but also extend to a part of thenon-display area NDA. The insulating interlayer 106 may have asingle-layer structure or a multilayer structure, with each layerincluding an inorganic material. For example, the inorganic material maybe metal oxide or metal nitride such as, for example, silicon oxide(SiO₂), silicon nitride (Si₃N₄), silicon oxynitride (SiON), aluminumoxide (Al₂O₃), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), hafniumoxide (HfO₂), zirconium oxide (ZrO₂), or the like.

The source electrode 107 and the drain electrode 108 are disposed on theinsulating interlayer 106. Each of the source electrode 107 and thedrain electrode 108 may have a single-layer structure or a multilayerstructure, with each layer including a metal known in the art. The metalmay include at least one of, for example, aluminum (Al), platinum (Pt),palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni),neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca),molybdenum (Mo), titanium (Ti), tungsten (W), copper (Cu), and the like.The source electrode 107 and the drain electrode 108 are each disposedto contact an area of the active layer 103. For example, the insulatinginterlayer 106 and the gate insulating layer 104 are formed to expose asource area and a drain area of the active layer 103 through openings,and the source electrode 107 and the drain electrode 108 are formed tofill the openings to contact the source area and the drain area of theactive layer 103, respectively.

The thin film transistor 100 a is electrically connected to the OLED 100b to drive the OLED 100 b and is covered with and protected by aninsulating layer 109. The insulating layer 109 may include an inclinedside portion in the non-display area NDA.

The insulating layer 109 eliminates a step (i.e., a height difference)caused by the thin film transistor 100 a and planarizes an upper surfaceabove the thin film transistor 100 a so as to substantially preventdefects from occurring in the OLED 100 b due to unevenness therebelow.The insulating layer 109 may have a single-layer structure or amultilayer structure including an inorganic insulating layer, an organicinsulating layer, or both of the inorganic insulating layer and theorganic insulating layer that are known in the art. Examples of amaterial forming the inorganic insulating layer may include but is notlimited to: SiO₂, Si₃N₄, SiON, Al₂O₃, TiO₂, Ta₂O₅, HfO₂, ZrO₂, bariumstrontium titanate (BST), lead zirconate titanate (PZT) or a mixturethereof. The organic insulating layer may include a common polymer knownin the art, and examples of a material forming the organic insulatinglayer may include but is not limited to: polymethylmethacrylate (PMMA),polystyrene (PS), polymer derivatives having a phenolic group, acrylicpolymers, imide polymers, arylether polymers, amide polymers, fluorinepolymers, p-xylene polymers, vinyl alcohol polymers, or blends thereof.In addition, the insulating layer 109 may be formed as a compositelaminate including an inorganic insulating layer and an organicinsulating layer.

On the insulating layer 109, the OLED 100 b is disposed. The OLED 100 bis electrically connected to the thin film transistor 100 a, andincludes a first electrode 110, a second electrode 113 opposing thefirst electrode 110, and an intermediate layer 112 interposed betweenthe first electrode 110 and the second electrode 113.

The first electrode 110 is disposed on the insulating layer 109 and maybe electrically connected to the thin film transistor 100 a,specifically to the drain electrode 108, through a contact hole definedin the insulating layer 109. The first electrode 110 may have variousshapes, for example, may be patterned into an island shape. The firstelectrode 110 may be a reflective electrode, and may include areflective layer including, for example, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd,Ir, Cr or a compound thereof, and a transparent or translucent electrodelayer disposed on the reflective layer. The transparent or translucentelectrode layer may include at least one of, for example, indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide(In₂O₃), indium gallium oxide (IGO), and aluminum zinc oxide (AZO).

The second electrode 113 which is disposed to oppose the first electrode110 may be a transparent or translucent electrode. For example, thesecond electrode 113 may include a metal thin film that has a low workfunction and includes, for example, Li, Ca, lithium fluoride (LiF)/Ca,LiF/Al, Al, Ag, Mg, or compounds thereof. In addition, an auxiliaryelectrode layer or a bus electrode that includes a transparent electrodeforming material such as, for example, ITO, IZO, ZnO, or In₂O₃ may befurther provided on the metal thin film. Accordingly, the secondelectrode 113 may transmit the light emitted from the organic lightemitting layer included in the intermediate layer 112. That is, thelight emitted from the organic light emitting layer may be emitteddirectly toward the second electrode 113 or may be directed toward thesecond electrode 113 after being reflected by the first electrode 110which is formed as a reflective electrode.

The display unit 100 is not limited to the top emission type. Forexample, in an exemplary embodiment of the present invention, thedisplay unit 100 may be a bottom emission type in which light emittedfrom the organic light emitting layer is emitted toward the substrate101. In such a case, the first electrode 110 may be a transparent ortranslucent electrode, and the second electrode 113 may be a reflectiveelectrode. In addition, in an exemplary embodiment of the presentinvention, the display unit 100 may be a double-sided emission type thatemits light toward both top and bottom directions.

In an exemplary embodiment of the present invention, a pixel defininglayer 119 including an insulating material may be disposed on the firstelectrode 110 and between the insulating layer 109 and the encapsulationlayer 300. The pixel defining layer 119 exposes a predetermined area ofthe first electrode 110, and the intermediate layer 112 including anorganic light emitting layer is disposed in the exposed area. That is,the pixel defining layer 119 defines a pixel area of the OLED. The pixeldefining layer 119 may include at least one organic insulating materialof, for example, polyimide, polyamide, an acrylic resin,benzocyclobutene, and a phenol resin, and may be formed by spin coating.

The organic light emitting layer included in the intermediate layer 112may include a low molecular weight organic material or a high molecularweight organic material. In addition to the organic light emittinglayer, the intermediate layer 112 may further include functional layersknown in the art, e.g., a hole transport layer (HTL), a hole injectionlayer (HIL), an electron transport layer (ETL), and an electroninjection layer (EIL) in a selected manner.

Although only one OLED is illustrated in FIG. 1 , the display unit 100may include a plurality of OLEDs 100 b. Each OLED 100 b may form onepixel, and a red, green, blue, or white color may be realized in eachpixel. In addition, a color conversion layer or a color filter forconverting the emitted light into a predetermined color may be furtherprovided.

The encapsulation layer 300 seals the display unit 100 to substantiallyprevent the display unit 100 from being deteriorated. For example, theencapsulation layer 300 may protect the display unit 100 from externaloxygen and moisture. The encapsulation layer 300 may have a multilayerthin film structure in which inorganic layers and organic layers arealternately stacked.

In an exemplary embodiment of the present invention, the encapsulationlayer 300 includes a first inorganic layer 310 disposed on the OLED 100b and extending from the OLED 100 b to the non-display area NDA, anorganic layer 320 disposed on the first inorganic layer 310, a secondinorganic layer 330 disposed on the organic layer 320 and extending fromthe organic layer 320 to the non-display area NDA, and an organicpattern layer 340 spaced apart from the organic layer 320 in thenon-display area NDA and disposed between the first inorganic layer 310and the second inorganic layer 330.

The first inorganic layer 310 may seal the OLED 100 b and may extend tocover a portion of the non-display area NDA, thereby securely preventingpermeation of oxygen or moisture into the OLED 100 b. The firstinorganic layer 310 may have a single-layer structure or a multilayerstructure, with each layer including: metal oxide or metal nitride knownin the art. For example, the first inorganic layer 310 may include atleast one kind of inorganic material selected from: silicon oxide(SiO₂), silicon nitride (Si₃N₄), silicon oxynitride (SiON), aluminumoxide (Al₂O₃), aluminum nitride (AlN), aluminum oxynitride (AlON),titanium oxide (TiO₂), titanium nitride (TiN), tantalum oxide (Ta₂O₅),tantalum nitride (TaN), hafnium oxide (HfO₂), hafnium nitride (HfN),zirconium oxide (ZrO₂), zirconium nitride (ZrN), cerium oxide (CeO₂),cerium nitride (CeN), tin oxide (SnO₂), tin nitride (Sn₃N₄), andmagnesium oxide (MgO).

The organic layer 320 covers a part of the first inorganic layer 310 andalleviates the internal stress of the first inorganic layer 310 or fillsmicrocracks and pinholes of the first inorganic layer 310, therebyenhancing effects of preventing permeation of moisture or oxygen. Theorganic layer 320 may have a single-layer structure or a multilayerstructure, with each layer including a polymer known in the art. Forexample, the organic layer 320 may include at least one kind of organicmaterial selected from: acrylic resins, methacrylic resins, isopreneresins, vinyl resins, epoxy resins, urethane resins, cellulose resins,phenylene resins, and imide resins. Moreover, the organic layer 320 mayinclude small organic molecules which may be crosslinked afterwards. Theorganic layer 320 is disposed so as to cover a part of the firstinorganic layer 310, and thus an area of the organic layer 320 may beless than an area of the first inorganic layer 310 and an area of thesecond inorganic layer 330 to be described. The part of the firstinorganic layer 310 covered by the organic layer 320 may include majorportion in the display area DA and may also include some portion in thenon-display area NDA.

The second inorganic layer 330 may be disposed on the organic layer 320and may extend from the organic layer 320 to cover a part of thenon-display area NDA, thereby securely preventing permeation of oxygenand moisture. The second inorganic layer 330 may have an areasubstantially equal to an area of the first inorganic layer 310 in aplan view. The second inorganic layer 330 may have a single-layerstructure or a multilayer structure, with each layer including: metaloxide or metal nitride known in the art. For example, the secondinorganic layer 330 may include at least one kind of inorganic materialselected from: SiO₂, Si₃N₄, SiON, Al₂O₃, AlN, AlON, TiO₂, TiN, Ta₂O₅,TaN, HfO₂, HfN, ZrO₂, ZrN, CeO₂, CeN, SnO₂, Sn₃N₄, and MgO. Thecomponent of the second inorganic layer 330 may be substantially thesame as or different from the component of the first inorganic layer310.

In an exemplary embodiment of the present invention, since the firstinorganic layer 310 and the second inorganic layer 330 have asubstantially equal area and the organic layer 320 interposedtherebetween has an area less than the area of the first inorganic layer310 and the area of the second inorganic layer 330, there exists an areain the non-display area NDA where at least a portion of the firstinorganic layer 310 and at least a portion of the second inorganic layer330 contact each other. In such a non-display area NDA where the firstand second inorganic layers 310 and 330 contact each other, peeling islikely to occur at an interface between the first and second inorganiclayers 310 and 330, and there is a high possibility that stress isconcentrated at the interface and cracks are generated. In particular,when an impact caused by an external force is applied to an area of thenon-display area NDA where the first and second inorganic layers 310 and330 contact each other acts as a weak point, cracks may easily occur atthis weak point as illustrated in FIG. 3 , thereby inevitably resultingin defective products.

According to an exemplary embodiment of the present invention, theorganic pattern layer 340 that is spaced apart from the organic layer320 is additionally formed between the first inorganic layer 310 and thesecond inorganic layer 330 which contact each other in the non-displayarea NDA. For example, the first inorganic layer 310 and the secondinorganic layer 330 may contact each other in the non-display area NDAwhere the organic layer 320 and the organic pattern layer 340 are notdisposed between the first inorganic layer 310 and the second inorganiclayer 330. The organic pattern layer 340 absorbs the stress between theinorganic layers 310 and 330 and imparts flexibility. Accordingly, theorganic pattern layer 340 may serve to realize a robust sealingstructure by mitigating impact due to external force and suppressingcrack occurrence. FIG. 4 is an SEM photograph showing a cross-sectionalstructure of an organic light emitting display device 10 including anorganic pattern layer 340 according to an exemplary embodiment of thepresent invention. As illustrated in FIG. 4 , crack does not occur atthe weak point where the first and second inorganic layers 310 and 330contact each other in contrast to that illustrated in FIG. 3 . This isdue to the formation of the organic pattern layer 340 overlapping theinclined side portion (e.g., an edge) of the insulating layer 109, andwill be discussed further below.

In such an exemplary embodiment described above, it is necessary todispose the organic pattern layer 340 at a specific position wherecracks are likely to occur relative to other areas, in consideration ofthe structure of the encapsulation layer 300 and the process efficiencyof the OLED display device 10. According to an exemplary embodiment ofthe present invention, the organic pattern layer 340 may be disposedapart from the organic layer 320 and between the first inorganic layer310 and the second inorganic layer 330 that contact each other in thenon-display area NDA. According to an exemplary embodiment of thepresent invention, the organic pattern layer 340 may be disposed at anarea in which at least a portion of the non-display area NDA where thefirst inorganic layer 310 directly contacts the second inorganic layer330, and at least a portion of an inclined side portion (e.g., an edge)of the insulating layer 109 and the organic pattern layer 340 overlapeach other in a plan view. At least a portion of the organic patternlayer 340 may overlap the insulating layer 109 of the display unit 100in a plan view. The organic pattern layer 340 disposed at theabove-describe position may absorb the stress between the inorganiclayers 310 and 330 that contact each other and may impart flexibility tosuppress cracking. In addition, the organic pattern layer 340 may alsobe disposed at positions other than the one described above to preventcracking by identifying the weak points such as the stress concentratedareas in the structure and applying the organic pattern layers 340 tothe weak point areas to release the stress.

The organic pattern layer 340 may be formed by allowing a part of theorganic layer 320, that is supposed to be removed during a process ofmanufacturing the organic layer 320, to remain, for example, on thefirst inorganic layer 310. Accordingly, the organic pattern layer 340may be disposed apart from the organic layer 320, but may include amaterial substantially the same as a material included in the organiclayer 320. For example, the organic pattern layer 340 may include atleast one kind of organic material selected from: acrylic resins,methacrylic resins, isoprene resins, vinyl resins, epoxy resins,urethane resins, cellulose resins, phenylene resins, and imide resins.In addition, in consideration of the structure of the encapsulationlayer and the effect of impact mitigation, the organic pattern layer 340may have a width of about 10 µm or more and a thickness of about 0.1 µmor more. For example, to substantially prevent an overlap with a monomerjetting line, the organic pattern layer 340 may have a width in a rangefrom about 10 µm to about 100 µm. In addition, not to affect the profileof the second inorganic layer 330, the organic pattern layer 340 mayhave a thickness in a range from about 0.1 µm to about 0.6 µm.

FIG. 1 exemplifies an embodiment in which the first inorganic layer 310,the organic layer 320, and the second inorganic layer 330 aresequentially stacked as an encapsulation layer, and the organic patternlayer 340 is disposed between the first inorganic layer 310 and thesecond inorganic layer 330 that contact each other in the non-displayarea NDA. However, the present invention is not limited thereto. Forexample, the stack structure of the inorganic layers and the organiclayers and the number of layers in the encapsulation layer are notparticularly limited, as long as there is the organic pattern layer 340between the inorganic layers that contact each other in the non-displayarea NDA. That is, the encapsulation layer 300 may further include aplurality of inorganic layers and a plurality of organic layers that arealternately disposed, and the number of times of lamination of theinorganic layers and the organic layers is not particularly limited aswell. For example, in an exemplary embodiment of the present invention,the encapsulation layer 300 may further include additional organiclayer(s), organic pattern layer(s), and inorganic layer(s), other thanthe organic layer 320, the organic pattern layer 340, the firstinorganic layer 310 and the second inorganic layer 330 shown in FIG. 1 .

FIG. 2 is a cross-sectional view illustrating an organic light emittingdisplay device according to an exemplary embodiment of the presentinvention. In FIG. 2 , the same reference numerals as those in FIG. 1denote the same members.

In the following description of FIG. 2 , the redundant descriptionsdescribed hereinabove with reference to FIG. 1 will not be provided, andonly differences will be described.

Referring to FIG. 2 , an OLED display device 11 according to the presentexemplary embodiment may further include a dam portion 120 disposed inthe non-display area NDA of the substrate 101, as compared with FIG. 1 .

The dam portion 120 disposed outside the display area DA maysubstantially prevent an organic material for forming the organic layer320 from flowing toward an edge of the substrate 101 when forming theorganic layer 320 of the encapsulation layer 300, and accordingly,formation of an edge tail of the organic layer 320 may be substantiallyprevented. The dam portion 120 may surround the display area DA and havea predetermined height to enclose the display area DA.

The dam portion 120 may include a material substantially the same as amaterial included in at least one of the insulating layer 109 and thepixel defining layer 119. The dam portion 120 may include a plurality oflayers. In an exemplary embodiment of the present invention, the damportion 120 may include a first layer 121 which includes a materialsubstantially the same as a material included in the insulating layer109, and a second layer 122 which is on the first layer 121 and includesa material substantially the same as a material included in the pixeldefining layer 119. However, the present invention is not limitedthereto. For example, in an exemplary embodiment of the presentinvention, the dam portion 120 may include one layer. Alternatively, inan exemplary embodiment of the present invention, the dam portion 120may include three or more layers. For process simplification, in anexemplary embodiment of the present invention, the first layer 121 ofthe dam portion 120 and the insulating layer 109 may be formed by anidentical process, and/or the second layer 122 of the dam portion 120and the pixel defining layer 119 may be formed by an identical process.

The dam portion 120 may be formed in plural. In an exemplary embodimentof the present invention, the plurality of dam portions 120 may havedifferent heights. Within the plurality of dam portions 120, a height ofone dam portion 120 near an outer portion of the substrate 101 may begreater than a height of another dam portion 120 near an inner portionof the substrate 101. That is, the height of the dam portion 120 mayincrease toward the outer portion of the substrate 101.

In the OLED display device 11 illustrated in FIG. 2 , the firstinorganic layer 310 and the second inorganic layer 330 may extend to theoutside of the substrate 101 so as to cover the dam portion 120.Accordingly, the penetration of external moisture and oxygen to the OLEDdisplay device 11 may be delayed or blocked. In addition, since the damportion 120 substantially blocks an organic material from flowing towardan edge of the substrate 101 when forming the organic layer 320, theorganic layer 320 is to be disposed inside the dam portion 120 in thedisplay area DA and the non-display area NDA. In addition, the organicpattern layer 340 may be disposed between the dam portion 120 and aninclined side portion (edge) of the insulating layer 109. The inclinedside portion of the insulating layer 109 is inclined in a directiontoward the dam portion 120. At least a portion of the organic patternlayer 340 may overlap the insulating layer 109 of the display unit 100in a plan view. The first and second inorganic layers 310 and 330 maycover an outside surface of the dam portion 120 and may contact eachother outside the dam portion 120 in the non-display area NDA. Inaddition, the first and second inorganic layers 310 and 330 may contacteach other inside the dam portion 120 where the organic layer 320 andthe organic pattern layer 340 are not disposed.

The dam portion 120 may be disposed so as to contact at least a part ofthe power wiring 220. For example, the dam portion 120 may be disposedso as to overlap and contact at least an outer edge of the power wiring220. The dam portion 120 that includes a material substantially the sameas a material included in at least one of the insulating layer 109 andthe pixel defining layer 119 may have a good bonding strength withmetal. Accordingly, when the dam portion 120 is disposed to contact thepower wiring 220 that includes a metal material, the dam portion 120 maybe stably constructed with excellent bonding strength with the powerwiring 220.

Although FIG. 2 illustrates an example in which the dam portion 120 isdisposed to overlap an outer edge of the power wiring 220, however, thepresent invention is not limited thereto. For example, in an exemplaryembodiment of the present invention, the dam portion 120 may be disposedonly on the power wiring 220, or may be disposed so as to cover thepower wiring 220. Here, the power wiring 220 may be connected to thesecond electrode 113 via a wiring 116 for supplying power to the OLED100 b.

FIGS. 5, 6, 7 and 8 are cross-sectional views schematically showing amethod of manufacturing the organic light emitting display device ofFIG. 1 according an exemplary embodiment of the present invention.

Referring to FIG. 5 , the display unit 100 is formed on the substrate101, and the first inorganic layer 310 which is over the display unit100 and extends from the display unit 100 to cover a portion of thenon-display area NDA is formed.

The display unit 100 may employ various OLED displays known in the art,in addition to the configuration exemplified in FIG. 1 , and thus aspecific method of manufacturing the display unit 100 will be omitted.

The first inorganic layer 310 may include an inorganic material such asmetal oxide, metal nitride, or the like that are known in the art. Sucha first inorganic layer 310 may be deposited by a method such as, forexample, sputtering, atomic layer deposition (ALD), or chemical vapordeposition (CVD).

After the first inorganic layer 310 is formed, the organic layer 320 isformed as illustrated in FIG. 6 .

The organic layer 320 may include any organic material known in the art,e.g., monomers and/or polymers, without limitation. Such an organiclayer may be formed through various process methods known in the art andmay be formed by one of, for example, an inkjet method, a slit coatingmethod, a screen printing method, an evaporation method, and a chemicalvapor deposition (CVD) method.

After the organic layer 320 is formed, a part of the organic layer 320is removed as illustrated in FIG. 7 . More specifically, the tail of theorganic layer 320 is removed, and a part of the organic layer 320 isleft in the non-display area NDA to form the organic pattern layer 340that is spaced apart from the organic layer 320.

The organic pattern layer 340 may be formed by an ashing process using acleaning mask. The cleaning mask may be formed through aphotolithographic process. The ashing process is a dry etch process inwhich a gas such as oxygen (O₂), nitrous oxide (N₂O) or ammonia (NH₃) isaccelerated in a plasma state to remove carbon-based organic substancesremaining at the bottom to be cleaned. It is preferable that the organicpattern layer 340 is formed by an oxygen (O₂) ashing process. Forexample, after disposing a cleaning mask on the organic layer 320 in achamber, the ashing process is performed using the cleaning mask. Inparticular, according to an exemplary embodiment of the presentinvention, the pattern of the organic layer 320 to be removed may befreely controlled by partially modifying the design of the cleaning maskapplied to the ashing process, and thus the organic pattern layer 340 onone side portion (edge) of the insulating layer 109 remains and the tailof the organic layer 320 other than the one side portion is removed inthe non-display area NDA.

Any cleaning mask that is commonly used in the ashing process may beused without limitation, except that the design is partially modified.In addition, the conditions of the ashing process are not particularlylimited. For example, conditions such as the internal pressure of thechamber, the oxygen flow rate, or the applied power may be appropriatelyadjusted within the range known in the art.

Next, the second inorganic layer 330 is formed to cover the organiclayer 320 and further extends to cover a part of the non-display areaNDA, as illustrated in FIG. 8 .

The second inorganic layer 330 may be formed by, for example,sputtering, atomic layer deposition (ALD), chemical vapor deposition(CVD), or the like. The second inorganic layer 330 may include aninorganic material such as metal oxide or metal nitride that are knownin the art. For example, the second inorganic layer 330 may include amaterial substantially the same as or different from a material includedin the first inorganic layer 310 described above.

The method according to an exemplary embodiment of the present inventionmay further include forming the dam portion 120 disposed in thenon-display area NDA of the substrate 101. Since the dam portion 120 mayhave the configuration exemplified in FIG. 2 , a specific manufacturingmethod thereof will be omitted. For example, the dam portion 120 may beformed in a process substantially the same as a process in which atleast one of the insulating layer 109 and the pixel defining layer 119is formed with a material substantially the same as a material includedin the at least one of the insulating layer 109 and the pixel defininglayer 119. The dam portion 120 and at least one of the insulating layer109 and the pixel defining layer 119 may be formed of a photosensitivematerial through a photolithographic process. Accordingly, the damportion 120 and at least one of the insulating layer 109 and the pixeldefining layer 119 may be substantially formed simultaneously through anexposure process using a halftone mask by adjusting an exposure amount.However, the present invention is not limited thereto. For example, atleast one of a preliminary insulating layer and a pixel defining layermay be formed on the substrate 101 through spin coating process, an etchmask may be formed on at least one of the preliminary insulating layerand the preliminary pixel defining layer through an photolithographicprocess, and an etching process may be carried out through the etch maskto etch at least one of the preliminary insulating layer and thepreliminary pixel defining layer to form the dam portion 120 and the atleast one of the insulating layer 109 and the pixel defining layer 119simultaneously.

The OLED display device according to an exemplary embodiment of thepresent invention includes a separate organic pattern layer that mayabsorb stress and impart flexibility between inorganic layers thatdirectly contact each other in the non-display area NDA, and thus maysuppress cracking and achieve a robust structure of an encapsulationlayer. Such OLED display devices may be applied not only to flat paneldisplay (FPD) devices but also to any display devices such as, forexample, curved display devices, foldable display devices and flexibledisplay devices in the field of the present invention.

As set forth hereinabove, the OLED display device according to anexemplary embodiment of the present invention includes a separateorganic pattern layer that may absorb stress and impart flexibilitybetween the first inorganic layer and the second inorganic layer.Accordingly, the impact caused by an external force may be mitigated andthe crack generation may be suppressed, and thereby a robustencapsulation structure may be realized.

The OLED display device according to an exemplary embodiment of thepresent invention may form the organic layer and the organic patternlayer substantially simultaneously without using a separatemanufacturing process. Accordingly, the manufacturing cost of the OLEDdisplay device may be low.

While the present invention has been illustrated and described withreference to the exemplary embodiments thereof, it will be apparent tothose of ordinary skill in the art that various changes in form anddetail may be made therein without departing from the spirit and scopeof the present invention as defined by the appended claims.

What is claimed is:
 1. An organic light emitting display devicecomprising: a substrate comprising a display area and a non-displayarea; a thin film transistor disposed on the substrate in the displayarea; an insulating layer disposed on the thin film transistor; anorganic light emitting element disposed on the insulating layer andconnected to the thin film transistor; and an encapsulation layercovering the organic light emitting element, wherein the encapsulationlayer comprises: a first inorganic layer disposed on the organic lightemitting element and extending from the organic light emitting elementto the non-display area; an organic layer disposed on the firstinorganic layer; a second inorganic layer disposed on the organic layerand extending from the organic layer to the non-display area; and anorganic pattern layer disposed between the first inorganic layer and thesecond inorganic layer so as to be spaced apart from the organic layerin the non-display area, wherein at least a part of the first inorganiclayer and at least a part of the second inorganic layer contact eachother in the non-display area, and at least a part of the organicpattern layer overlaps an inclined portion on a lower surface of theencapsulation layer in a plan view.
 2. The organic light emittingdisplay device of claim 1, wherein the inclined portion of theencapsulation layer is positioned on a lower surface of theencapsulation layer facing the insulating layer in the non-display area.3. The organic light emitting display device of claim 1, wherein theinclined portion of the encapsulation layer is an inclined surfacecorresponding to an inclined side portion of the insulating layer. 4.The organic light emitting display device of claim 1, wherein theinclined portion of the encapsulation layer comprises a side portioninclined in a direction toward the non-display area.
 5. The organiclight emitting display device of claim 1, wherein the organic patternlayer is disposed at an area in which at least a part of the non-displayarea where the first inorganic layer and the second inorganic layercontact each other and at least a part of the inclined portion of theencapsulation layer overlap each other in a plan view.
 6. The organiclight emitting display device of claim 1, wherein a thickness of theorganic pattern layer is smaller than a thickness of the organic layer.7. The organic light emitting display device of claim 1, wherein theorganic pattern layer has a thickness of about 0.1 µm or more.
 8. Theorganic light emitting display device of claim 1, wherein the organicpattern layer has a width of about 10 µm or more.
 9. The organic lightemitting display device of claim 1, wherein a width of the organicpattern layer is equal to or smaller than a spacing between the firstinorganic layer and the second inorganic layer contacting each other inthe non-display area.
 10. The organic light emitting display device ofclaim 1, wherein the organic pattern layer comprises a material the sameas a material which the organic layer comprises.
 11. The organic lightemitting display device of claim 1, wherein the organic layer comprisesat least one kind of organic material selected from: acrylic resins,methacrylic resins, isoprene resins, vinyl resins, epoxy resins,urethane resins, cellulose resins, phenylene resins, and imide resins.12. The organic light emitting display device of claim 1, wherein thefirst inorganic layer and the second inorganic layer have an equal areain a plan view, and an area of the organic layer is less than an area ofthe first inorganic layer and an area of the second inorganic layer. 13.The organic light emitting display device of claim 1, wherein the firstinorganic layer and the second inorganic layer each independentlycomprises at least one kind of inorganic material selected from: siliconoxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminumnitride, aluminum oxynitride, titanium oxide, titanium nitride, tantalumoxide, tantalum nitride, hafnium oxide, hafnium nitride, zirconiumoxide, zirconium nitride, cerium oxide, cerium nitride, tin oxide, tinnitride, and magnesium oxide.
 14. The organic light emitting displaydevice of claim 1, further comprising a dam portion disposed in thenon-display area of the substrate.
 15. The organic light emittingdisplay device of claim 14, wherein the insulating layer comprises aside portion inclined in a direction toward the dam portion.
 16. Theorganic light emitting display device of claim 14, wherein the damportion is provided in plural and the plurality of dam portions havedifferent heights.
 17. The organic light emitting display device ofclaim 14, further comprising a pixel defining layer disposed between theinsulating layer and the encapsulation layer, the pixel defining layerdefining a pixel area of the organic light emitting element, wherein thedam portion comprises a material the same as a material which at leastone of the insulating layer and the pixel defining layer comprises. 18.The organic light emitting display device of claim 14, wherein the damportion comprises: a first layer comprising a material the same as amaterial which the insulating layer comprises; and a second layer on thefirst layer, the second layer comprising a material the same as amaterial which the pixel defining layer comprises.